Railway traffic controlling apparatus



y 1941. J. J; VANHORN RAILWAY TRAFFIC CONTROLLING APPARATUS Filed July 29, 1939 2 Sheets-Sheet 1 I VENTOR James Vimlzom.

1 H55 Ai'TORNEY MEEND YNN N July 15, 1941-.

J. J. VANHORN RAILWAY TRAFFIC CONTROLLING APPARATUS Filed July 29. 1939 2 Sheets-Sheet 2 HLS" v ATTORNEY 1 NNNU. m H wnm SEE 5 tween the two interlockings. I or both of the interlocking's are of the all-relay Patented July 15, 1941 warren STATES PATENTOFFlQE RAILWAY TRAFFIC CONTROLLING APPARATUS James J. Vanhorn, Swissvale; 1a., ass'ignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application July 29, 1939, Serial No. 287,235

7 Claims. (Cl. 246-25) My invention relates to railway traflic control- 3 I ling apparatus, and particularly to trafiic locking apparatus for railways.

When trafiic is to beoperated in either direction over a railway track extending between two spaced locations trailic locking apparatus is provided which commonly includes a traific locking circuit controlled jointly by two operators one at each end of the stretch of railway. Such traffic locking circuit is adapted to prevent the manipulation of trafiic governing signallevers or units for changing the direction of traffic on the f stretch of track between such two spaced locations while the stretch is occupied or while a traffic governing signal is displayed for a train to proceed into such stretch. When a traffic locking circuit extends between two attended interlocking stations or towers and is controlled by traffic levers included in respective interlocking ma chines, the trailic locking circuit is commonly arranged to permit signaling between the two opertors as an aid in the joint control of traflic be- In cases where one trolled by such circuit is set to display its proceed indication might result in the placing of the signal at stop and consequently interrupts a train movement.

Accordingly, a feature of my invention is the provision of novel and improved means for traffic locking between two spaced locations, and specifically between two interlockings, at least one of which is of the all-relay, automatic or remotely controlled type. Another feature of my invention is the provision of novel and improved means for traffic locking of the type here involved for which only two line wires are required for the traiiic locking circuit, and this circuit may be used for signaling between the operators as well as for controlling the wayside traflic governing signals. A further feature of my invention is the provision of apparatus for traffic locking of the type here contemplated wherewith interruption of the traffic locking circuit by an unauthorized movement of a traffic lever by the operator at the leaving end of the circuit is avoided. Other features and advantages of my invention will appear as the specification pro-- gresses,

I shall. describe two forms of apparatus embodying my invention, and shall then point out the novel features thereof in claims.

' In theaccompanying drawings, Fig. 1 is a di-- agrammatic view of one form of apparatus embcdying my invention when used for trafiic looking between an unattended interlocking location of a centralized 'traflic control system and an attended interlocking of the mechanical interlocked lever type. Fig. 2 is a diagrammatic view of another form of apparatus embodying my invention when'u'sed for tr'aificlocking between two all-relay interlockings.

In each of the two views like reference characters refer to similar parts.

Referring to Fig. 1, the lineargraph at-the topof the drawings illustrates a stretch of railway track extending between two spaced locations A and B at each of which an interlocking "is 10'-' cated, and' over whicfh stretch" of track trafiic moves in either direction. In the following description locations' A and B are at times referred to as interlockings A and'B, respectively. At location A the track is formed with a detector track section IT having a track switch SI leading to a siding track located therein and which switch has the usual wayside signals associated threwith at be readily understood by an inspec tion of Fig. 1. 7 At location B thetrack isformed with a detector track section CIT which has the usual wayside signals associated therewith for.

governing traffic therethrough. These wayside. signals at locationsfA and B may be of any one of the standard types and the control thereof is shown only mediates is required for an under-',

standing of my invention. It is sufii'cient to point out thatthe wayside signal RZA at location A governs traiiic moving eastbound from location A to location B,a ndthe wayside signal L2A atlocation B governstrafiic moving westbound from location B to'location A. At location A an un- A attended interlocking is located and hence thewayside or traffic governing signal RZA is'controlledv by .a relay or. control unit which in turn is governed by an operator vat a remote office stationas will be described hereinafter. At location B is located an attended interlocking havingmej T chanically 7 interlocked,levers,v such as, for example, 'an'electro-m'echanical interlocking machine. Hence Wayside signal LZA is controlled in part by a manually operable signal lever of the interlocking machine as will appear hereinafter.

The track between the locations A and B is preferably formed into insulatedtrack sections and as shown in Fig. 1 it is formed with two such sections MT and BIT. Each track section of the stretch is provided with any desired form of track circuit which circuit includes a track relay connected with the rails at one end of the section and which relay is here identified by the reference character R plus a prefix corresponding to the associated track section. The relationship of each track relay with its respective track sec-' tion is indicated conventionally by a dash line. It will be understood that automatic wayside signals may be provided between the locations A and B and controlled in accordance with wellknown practice.

Before proceeding further with the description, it should be pointed out that contact fingers of the track relays and other relays to be referred to later in the specification, are in many instances shown remote from the windings of the relays. In each such case, the contact finger is identified by the reference character corresponding to that of the relay by which it is operated plus a distinguishing numeral, and the contact finger is shown in the position corresponding to the normal position of the relay. Furthermore, it will be understood that each location A and B is provided with a suitable source of current such as a battery not shown. These two sources of current one at location A and the other at location B are preferably of the same voltage and in Fig. 1

the terminals of the battery at location A are identified by the reference characters BI and Cl, and the terminals of the battery at location B are identified by the reference characters B2 and C2.

Looking at the interlocking at location A, there is provided a remotely controlled relay for each of the wayside signals, the control relay RZHS for governing wayside signal R2A only being shown for the sake of simplicity since signal RZA is the only wayside signal at interlocking A which is involved in governing traffic moving eastbound to location B and the description of the control of the other wayside signals is not required for a full understanding of my invention.

The relay R2HS controls the operating circuit for wayside signal RZA in the usual and wellknown manner and it is sufficient to point out that when relay RZHS is energized and picked up closing front contact 150, the signal R2A is operated to a proceed position and when relay R2HS is deenergized and released closing back contact I51, the signal R2A is operated to the stop position. The system for controlling signal control relay RZHS and the other signal control relays not shown at interlocking A from a remote office station may be a direct wire system using a line wire for each relay, or it may be a code system using a single two-wire line circuit for selectively controlling all the relays. I shall assume that the remote control of the interlocking at location A is effected by a centralized traffic control system of the time code type covered in the United States application for Letters Patent Serial No. 600,786, filed March 23, 1932, by L. V. Lewis, for Remote control systems, and to which application reference is made for a full understanding of such systems. It is sufiicient for the present application to point out that a line coding unit CU shown conventionally is located at interlocking A and is selectively operated in response to code signals sent from a central office station not shown. When the coding unit CU is operated, positive energy is made to appear at the terminals 2, 3, 5, E and 1 of the unit according to the code signal operating the unit. Positive energy is applied to the terminal 5 only during the reception of the code signal corresponding to signal control relay RZI-IS and that relay is picked up over a pick-up circuit easily traced and which circuit includes the usual traffic control indicated by contact 30. Positive energy remains on terminal 6 subsequent to the reception of such code signal to retain relay RZHS picked up over a stick circuit including terminal 6, either front contact 15 of a relay IEF or front contact 16 of a relay IEFS, both of which relays will be later referred to, winding of relay R2HS, front contact 11 of track relay ITR. and terminal Cl. Hence, once a code signal is received by coding unit CU for operating relay RZHS that relay is picked up, and retained picked up for operating signal R2A until such time as a code signal is received from the office station for removing positive energy from terminal 6 or trafiic causes contact l5, 75 or 11 to be opened in a manner to later appear. In a similar manner, a traffic control relay LIFS is energized and picked up in response to a code signal that causes positive energy to appear at terminal 2 of unit CU, and relay LIFS is retained picked up subsequent to such code signal by means of a stick circuit connected with terminal 3 of unit CU to which terminal positive energy is applied subsequent to the code signal that picked up relay LIFS until such time as a code signal is received by unit CU for deenergizing the relay LIFS. Also, a relay IUS is energized and picked up in response to a code signal that operates unit CU to cause positive energy to appear at terminal I of unit CU, relay IUS being picked up only during the reception of the respective code signal since positive energy is made to appear at terminal I only during the reception of the code signal. The function of relays LIFS and IUS will appear when the operation of the apparatus is described.

An indication relay IFK is associated with coding unit CU for applying at times positive energy to terminals l3 or 16. As described in the aforementioned Lewis application Serial No. 600,786, positive energy when applied to certain terminals of the coding unit causes the coding unit to transmit an indication code signal to the central office station for governing indication or signaling devices. As illustrated conventionally by dash lines, a signaling unit or indication bell OB at the office station is sounded in response to the code signal transmitted when positive energy is applied to terminal 13, and another signal unit or indication lamp OL is illuminated in response to the code signal transmitted when positive energy is applied to terminal [6. Positive energy is applied to terminal l3 and I6 over simple circuits respectively including front contact 3| and back contact 32 of indication relay IFK. Indication relay IFK in turn is controlled over a pick-up circuit and a stick circuit. The pick-up circuit extends from terminal BI of the current source over front contact 33 and reverse polar contact 34 of relay IEF, winding of relay IFK and to terminal CI. The stick circuit involves terminal Bl, front neutral contact 33 of relay IEF, front contact 35 and winding of relay IFK and terminal CI.

The apparatus at interlocking A also includes a slow release repeater relay EFA which is controlled over a simple circuit including front contact 18 ofrelay 'IEF, A traffic followingl'elay IEFS is also provided for the apparatus at interlocking A and this relay is controlled over a pick-up circuit which extends from terminal Bl over back contact I! of track relay AlTR, 'front contact 72 of relay EFA, Winding of relay l EFS and to terminal CI. A stick circuit is provided for relay IEFS which includes two paths one path of which is completed over back contact H of track relay Al TR and its own front contact 73, and the other path of whichis completed over back contact 14 of relay EFA and front contact 13. The function of relay EFA and of the traffic following relay IEFS will appear hereinafter.

Looking at the interlocking at location B, the interlocking machine includes a traific lever 30L and a wayside signal lever, 2L which levers are mechanically interlocked in the well-known inanner but which is not shown. 'The signal lever 2L is normally positioned in a center position and is operable to a left-hand position Where a contact member 36 engages a stationary contact 31, contact member 36 being also adaptable of engaging a stationary contact 29 at the normal position L of the lever. A signal control relay LZAH is governed by the signal lever 2L. The manner whereby relay L2AH is governed by lever 2L may be any one of the standard arrangements in presentday use and as here shown the circuit for relay LZAH includes terminal B2, contact 3537 of lever 2L, front contact 28 of a stick relay WFS; winding of relay LEAH, a traffic controlled contact 2'! and terminal C2. Relay WFS in turn is shown controlled over ,a pick-up circuit and a stick circuit, the pick-up circuit extending from terminal B2 over lever contact 3fi'29, winding of relay F IFS and to terminal CZ and the stick circuit extending from terminal B2 over front contact of track relay Cl'IE, front contactgfi and winding of relay WFS and to terminal C2. It follows that when signal lever 2jL is released by the mechanical interlocking and is moved to its left-hand position, the signal control relay L2AH is energized and picked up closing front contact [52 for operating the signal LZA to a proceed position. when 'a train advances past signal LEA and enters section ClT to shunt track relay CITR, the stick relay WFS is deener giz"ed causing relay LEAH to be deenerg'ized and re- 5 leased closing back contact I53 to operate signal L2'A to a stop position. To reehi'gib'e signal control relay LEAH for operating signal LZA for a following train, the signal lever 2L mustflrst be replaced at its normal position to pick up relay s- WFS and then operated again to its left-hand position. V v i The traffic lever 33L is operable to a normal position N, a reverse position R and to an indication position D. The lever L is previdcd with a series of contacts 33 to 55, inclusive, for selec-' tively closing circuits at'diiferent positions cf the lever. These contacts operated by lever 33L are shown conventionally in the well-known manner and each contact is provided with a reference character N, R or D to indicate the position of the lever 35L at which the" contact is closed. The traiiic lever 39L has connected therewith a see: ment 5% provided with a notch 61' adaptableof engaging a locking cl'og' i of a lock magnet 49, the arrangement being such that lever 35L is' arrested in its movement from normal position N to reverse position R at indication position D until such time as magnet 49 is energized to lift locking dog 48 out of engagement with notch 41.

An indication relay SBFK is associated with lever 30L for controlling a signaling unit or ine dication bell TB and asec'ond signaling unit or indication lamp TL. The bell TB is governed over either of two circuits, a first one of which includes front contact 50 of relay SBFK, and a second'one of which includes front contact 5| of a relay 33F? to be referred to later and contact &3 closed at the normal position N of lever 30L. The lamp TL is illuminated over back contact 52 of indication relay BOFK,

,In order to permit trafilc to move in either direction between locations A and B, the two inte'rlockings are associated by a traflic locking circuit and which circuit includes a directional relay at each location, eastbound directional relay !EF being located at location A and westbound directional relay BOWF being located at location B. This trafiic locking circuit is completed between the two locations over two line wires 53 and 54 in which there are preferably f interposed front contacts of the track relays of the intervening track sections, front contacts 55 and 56 of track relay AiTR and front contacts 57 and 58 of track relayBiTR being interposed in the wires 53 and 54 as will be readily understood by an inspection of Fig. 1. That is to say, the traffic locking circuit is held open as long as the stretch of track between locations A and B is occupied.

The directional relays IEF and 3BWF are preferably of the retained neutral polarized type, that is, the neutral front contacts are retained closed during a reversal of the energizing current, such relays being Well-known to the art.

A directional repeater relay 3GFP is provided at location B and its winding'is interposed in the trafiic locking circuit as will shortly appear.

The traffic locking circuit is also governed by I manually controlled devices one at each interk locking. To be explicit, at interlocking A the relay LIFS which. is controlled by the operator at the central oilfice station through the central.- ized traffic control system serves as'a manually controlled device for controlling the traffic locking circuit, the front contacts 59 and (iii of relay LIFS or the back contacts 6! andtfi of that'relay being interposed in the circuit in a manner to be described hereinafter. At interlocking B the traflic lever 30L serves as a manually controlled.

device for governing the traliic lockingcircuit;

the contacts 33 and 39 being interposed in the circuit when the lever is set at its normal posi-' tion and the contacts 48 and M being interposed locking circuit is also governed by two polechang 'ers one located at each interlocking. At interlocking'A the front contacts 63 and 64 and the back contacts E5 and 66 of relay lUS serve'to v pole change the traflic locking circuit. At inter: locking B a push button BP is provided, the trafiic locking circuit being completed over the contacts a El and 658 when the push button is released'and being completed over contacts 59 "and Tiinwh en V v the push button is depressed In describing the operation of the apparatus of Fig. 1, I shall assume the apparatus first occupies its normal position, that s, thepcsitiohq shown in Fig. 1, so that'the eastboundfdirection for traillc is established. That is to say, the op erator of the centralized traffic control system is normally given control of traffic over the territory between interlockings A and B. Under this normal condition of the apparatus the trailic control relay LIFS at interlocking A is energized v and the trafiic lever 3iiL at interlocking B is set at its normal position N. The trafiic locking circuit is supplied with current from battery at interlocking B and the circuit can be traced from terminal 132 over Winding of repeater relay 30FP, normally closed contact 61 of push button BP, contact 38 of traffic lever 36L, line wire 53, front contacts 51 and 55 of track relays BITR and AITR, respectively, front contact 59 of traflic control relay LIFS, winding of directional relay IEF, front contacts 60, 56 and 58 of relays LIFS, AITB, and BiTR, respectively, line wire 54, contact 39 of lever 3ilL, normally closed contact 68 of push button BP and to terminal (32 of the battery at interlocking B. The directional relay IEF at interlocking A is energized to close its neutral front contacts and to close its normal polar contacts since the polarity of the current normally flowing in the trafiic locking circuit is such that the directional relay IEF is energized at normal polarity. The repeater relay 39F? at location B is proportioned so that the voltage impressed across its winding by the one battery B2-C2 is not sufficient to energize the relay at its pick-up value and the relay is normally released closing its back contacts. This normal condition of the traflic locking circuit is indicated at the central ofiice station by the illumination of lamp OL because positive energy has been applied to terminal E6 of the coding unit over back contact 32 of indication relay IFK. At interlocking B, lamp TL is illuminated over back contact 52 of indication relay IiiiFK to indicate the normal condition of the traffic locking circuit to the operator at interlocking B,

If the operator at the central oflice station desires to operate signal RZA for directing an eastbound train from location A to location B, he transmits a code signal for operating the coding unit CU to pick up the signal control relay RZHS, relay RZHS being first picked up over its pick-up circuit when positive energy is made to appear at terminal in response to the code signal and is then retained energized over its stick circuit by the positive energy applied to terminal 6 since the directional relay IEF is now picked up closing front contact 15. When the train advances past signal R2A and enters section IT and shunts track relay ITR opening front contact Ti, the relay RZHS is released and causes signal RZA to assume its stop position. With the train advancing into section AIT to shunt track relay AITR opening front contacts 55 and 56, the traflic locking circuit is opened and directional relay IEF is deenergized. and released. The repeater relay EFA is now deenergized and releases at the end of its slow release period. During the slow release period of relay EFA, current is supplied to the traffic following relay IEFS over its pick-up circuit since track relay AlTR, is now deenergized closing back contact II. The traffic following relay IEFS is then retained picked up over its stick circuit until such time as the eastbound train arrives at location B and vacates section BIT so that the traflic locking circuit is reclosed and the directional relay IEF is reenergized and picked up causing the repeater relay EFA to be again picked up. In the event the operator at the central ofiice station desires to dispatch a second or following eastbound train from location A before the first train has arrived at location B, he sends a code signal to operate unit CU for again energizing the signal control relay RZHS, relay RZHS being retained energized over its stick circuit including front contact 16 of traffic following relay IEFS. It follows that under the normal condition of this apparatus the operator of the centralized traffic control system can dispatch eastbound trains from location A.

With the apparatus at its normal condition and assuming the operator an, interlocking B desires to send a westbound train to location A, be signals to the operator at the central oflice station by depressing the push button BP for a brief interval causing the current supplied to the trafiic locking circuit to be pole changed so that directional relay IEF at location A is reversed closing its reverse polar contact 34 during the interval push button BP is depressed, the neutral contact of relay IEF remaining closed, however, due to relay IEF being of the retained neutral type. With reverse polar contact 34 of relay IEF closed the indication relay IFK is picked up and is then held energized over its stick circuit after the push button Bl? is released and the traffic locking circuit reenergized at normal polarity. With relay IFK picked up closing front contact 3|, positive energy is applied to terminal [3 of coding unit CU and an indication code signal is transmitted to the central oflice which causes bell OB to sound informing the operator at the central ofiice station that the operator at location B desires a reversal in the direction of trafiic. The lamp 0L at the central office station is, of course, extinguished when relay IF'K is picked up.

If the operator at the central office station consents to a reversal in the direction of traific, he signals this fact to the operator at location B by transmitting a code signal which operates unit CU to deenergize traffic control relay LIFS. With relay LIFS released opening front contacts 59 and 60, and closing back contacts 6! and 62, the traflic locking circuit is transferred from directional relay IEF to the source of current at location A. The traffic locking circuit can now be traced from terminal B2 at location B over winding on relay 30FP, the elements 61, 38, 53, 51, 55, 6|, back contact 19 of relay IEFS, front contact of an approach locking relay MR not shown but which is associated with signal RZA in the usual manner front contact 8| of track relay ITR, back contact 65 of relay IUS, terminal CI to terminal Bl of the battery at location A, back contact 66 of relay IUS, front contact 82 of relay ITR, front contact 83 of relay MR, back contact 84 of relay IEFS, the following elements 62, 56, 58, 54, 39, 63 and terminal C2. Since the two batteries at the two interlocking locations are interposed in the traffic locking circuits in series the increased voltage impressed on the repeater relay 3BFP is suflicient to cause that relay to be picked up closing front contact 5| so that the bell TB is sounded to signal to the operator at location B that the operator of interlocking A consents to a reversal in the direction of tramc. The operator at location B next moves the traffic lever 30L to its indication position where contacts 44 and 45 are closed, so that the lock magnet 48 is connected across the traffic locking circuit for energization thereof by the battery at location A, the contacts 38 and 39 of lever 30L being now opened so that the repeater relay 30FP and the battery at location A are disconnected from the trafiic locking circuit. The magnet 49 is energized to lift locking dog 48 with the result that the lever 30L is released and can be moved to its full reverse position R. where contacts 40 and 4| are closed to connect the directional relay 30WF with the trafiic locking circuit for energiza-.

tion of that relay by the battery at location A, the connection being such that relay SDWF is energized at normal polarity. With trafiic lever 30L moved to its reverse position, the mechanical interlocking releases signal lever 2L and the operator at interlocking B can cause signal LZA to be operated to a proceed position by moving lever 2L to its left-hand position causing relay LZAH to be energized and picked up in the manner previously explained. With the direction of traflic established for westbound trains by the traflic locking circuit, the operator at location B can dispatch trains westbound to location A by operating signal lever 2L in the manner explained hereinbefore. It is to be observed that whenthe trafiic locking circuit is set for westbound trafiic the switch SI can be used for trains moving to the siding track without affecting the traffic locking circuit because with switch Si reversed contacts S|24 and SI-23 of the usual switch circuit controller are moved to the positions shown by dotted lines in Fig. 1 to complete the traflic locking circuit.

With westbound direction established and assuming the operator of interlocking A desires a reversal in the direction of trafiic, he signals to the operator at location B by sending a code signal which operates unit CU to pick up relay IUS for a brief interval. With relay IUS picked up closing front contacts 63 and 54 the trafiic locking circuit is pole changed and directional relay 3&WF is energized at reverse polarity closing reverse polar contact 9! interposed in the pick-up circuit of indication relay 3BFK. With indication relay 3BFK picked up to close front contact and open back contact 52, the bell TB is sounded and the lamp TL is extinguished to inform the operator at location B of the desire on the part of the operator of the interlocking at location A for a reversal in the direction of traffic. If the operator at location B consents to the reversal in the direction of trafiic he places the traffic lever 35L back to its normal position. The operator of interlocking A after having transmitted a code signal for operating relay IUS next sends the code signal effective to reenergize relay LIFS and that relay is picked up to transfer the traflic locking circuit back to the eastbound directional relay lEF and the eastbound direction of traflic is reestablished.

It is to be noted that signaling is effected between the operator of interlocking B and the operator of interlocking A over the two-wire line circuit by using polarized relays of the retained neutral type which permit this signaling between the operators without affecting the control of the wayside signals. For example, in the case the relay RZHS is energized and signal R2A operated to a proceed position for an eastbound train and the operator at interlocking B depresses the push but-ton BP for signalinga desire for a reversal in the direction of trafiic, the front neutral contact 15 of directional relay IEF remains closed during the reversal in the energization of relay IEF and the position of signal RZA is not affected. Furthermore, the use of a repeater relay 35F? which requires double line voltage to pick up that relay prevents possible false picking up of relay 39FP due to a cross on the line circuit which might result in false signaling to the operator at interlocking B of a desire for a reversal in the direction of trafiic.

Referring to Fig. 2,the track layout is the same as in Fig. 1. The interlockings A and B of Fig. 2 are both of the all-relay type, that is, the signal functions are controlledv by levers having no mechanical interlocking. The interlocking A includes a trailic lever A55, and the interlocking B includes a traffic lever 7133. Each lever A5 and. B6 is operable to a normal position N and to a reverse position R and each is, of course, noninterlccked with the other levers of the associated machine and has no lever lock magnet.

traffic locking circuit including two line wires 53, and 54 extending between, interlockings A andjB the same as in Fig. 1 is associated with levers A 6 and B6 for governing relays at each of the two locations for the control of, trafiic between the two'interlockings and which relays are similar to the relays of Fig. 1 except as will be noted hereinafter. In other words, the levers A6 and B6 form' two manually controlled devices for goyerningthe. trafiic locking circuit. Twomanually operable push buttons BPI and BP2 are provided at locations A and B, respectively, for at times pole changing the traffic locking circuit.

It is believed that the apparatus of Fig. 2 can best be understood by a description. of its opera.-

tion. Under normal. conditions, both levers A6 and B6 are set at their normal positions for conditioning the traffic locking circuit as required to establish eastbound direction of traffic. With lever B6 set at its 'normalv position, closing normal contact 83;, a repeater relay B6? is energizcol over a, simple pick-up circuit easily traced, relay BGP being also provided with a stick circuit which includes ba'ck contact 94 of a directional relay BVVF and front contact 95 of a directional repeater relay EFP. The traffic locking circuit under this normal condition can be traced from terminal B2 atinterlcoking B over front contact 915 of an approach locking relay LZMR associated. with signal 1 2A in the usual manner but not shown since it forms no part of my invention,ba ck contacts 9] and 98 of directional relay G WF and traiiic following relay BWFS, respectively,winding of directional repeater relay EFP,

normally. closed contact 99 of push button. BP2,

front contact Hill of relay BtP, line wire 53, front contacts 51 and 55 of track relays BlTR'and A'I'I'B, respectively; back contact [ill of a repeater relay A5}? at location A, normally closed contact 502 of lever Ai winding of directional relay SEF, "a second normally closed contact I03 of lever A5 back contact l M of relay ASP, front contacts 56 and 58 of relays AITR and BITR, respectively, line wire 54, front contact I05 of relay B6B, normally closed contact I06 of push button B92 and terminal C2. Directional relay BEF at location A and directional repeater relay EFP at location B are now energized and picked up, the polarity of the current being such that the directional relay EEF, which is of the retained neutral polarized type, is energized at normal polarity. With relay EFP picked up closing front contact I01, the lamp TL at location B is illuminated to inform the operator of the closed conditionof the traffic locking circuit. Also, lamp OL at location'A is illuminated over front contact I08 of directional relay SEF to indicate the closedconditionof the trafiic locking circuit to the operational; location A. With directional relay-GEFpickedup ciosingfront contact I09, slow release repeater relay EFA-is energized and picked up. If the operator at location A nowv desires to send a train eastbound to location B, he moves a contact I54 to operate signal R2A to a proceed position. The circuit for relay RZAH includes terminal BI, front contact III of repeater relay EFA, lever contact I Iii, front contact H2 of track relay ITR, winding of relay RZAH and terminal CI.

As the eastbound train advances past signal RZA and enters track section IT to shunt track relay ITR opening front contact H2, the signal control relay RZAH is released closing back contact I55 to set signal RZA at stop. As the train advances into section AIT and shunts track relay AITR, the traflic locking circuit is opened at front contacts 55 and 56 of relay AITR and the directional relay BEF at location A and the directional repeater relay EFP at location B are deenergized and released. The slow release repeater relay EFA is now without current due to the opening of front contact I09 of relay BEF and relay EFA is released at the end of its slow release period. During the slow release period of relay EPA and because back contact 'II of track relay AITR is now closed, current is supplied to the traffic following relay BEFS and that relay is picked up and then held energized over its stick circuit subsequent to the release of the repeater relay EFA until such time as the eastbound train arrives at location B to vacate track section BIT and restore the trafiic locking circuit so that the directional relay BEF is reenergized causing relay EPA to be also reenergized. With the trafiic following relay BEFS picked up closing front contact H3, the signal control relay R2AH can be reenergized to permit following moves from location A while the first train is between locations A and B.

It is to be noted that with signal R2A operated for an eastbound movement and an unauthorized movement of traflic lever B6 at location B takes place, such movement does not cause signal R2A to be set at stop because repeater relay BBP is retained energized over its stick circuit when lever contact 93 of lever B6 is open and hence such unauthorized movement of lever B6 does not affect the traffic locking circuit. Again, it should be noted that should the operator at location B depress push button BP2 in an attempt to signal to the operator at location A while the wayside signal R2A is set at a proceed position for an eastbound movement, the wayside signal R2A is not set at stop because the directional relay BEF is of the retained neutral type and a reversal in its energizing current due to the operation of the pole changing push button BP2 at location B does not affect the position of front contact I09 of relay SEF. It should also be noted that as long as the train occupies the stretch and the traffic locking circuit is open so that directional relay BEE and repeater relay EFP are released, both lamps L and TL are dark to indicate this condition of the trailic locking circuit to the two operators.

Assuming that the apparatus of Fig. 2 is normal and the operator at location B desires to have the direction of traffic reversed so that he can 'send a westbound train from location B, the opreverse polarity closing its reverse polar contact H4. -A circuit including front contact H5 and;

reverse polar contact I I 4 of relay BEF is closed to operate the bell OB to inform the operator at location A that a reversal in the direction of traffic is desired. If the operator at location A agrees to a change in the direction of traflic, he moves his lever A6 to its reverse position where contact H6 is closed causing repeater relay AGP to be picked up opening back contacts IUI and I04 and closing front contacts I I1 and I I8 to transfer the traffic locking circuit from the directional relay GEF to the current sourceat location A. The connection of battery at the location A is such as to oppose the battery at location B with the result that the repeater relay EFP at location B is deenergized and released to open front contact I01 interposed in the circuit for lamp TL so that lamp TL becomes dark to inform the operator at location B that the operator at location A agrees to a reversal in the direction of traflic. The lamp 0L at location A is also dark since the directional relay GEF is now released to open front contact I08.

The operator at location 3 now moves his traffic lever B6 to its reverse position opening contact 93 and closing contacts H9 and I20 so that when repeater relay BSP is released to close back contacts I2I and I22 the traffic locking circuit is connected with the directional relay BWF and that relay is picked up by the current supplied from the battery of location A. The

traffic locking circuit is'now established from I2I, H9, winding of directional relay GWF, I20,

I22, 54, 58, 55, H8, I21 and terminal CI. Directional relay GWF is now picked up and its normal polar contacts are closed since the direction of current is such as to energize relay GWF at normal polarity. Also, the directional repeater relay WPF at location A is picked up. The closing of front contact I28 of relay WFP illuminates lamp 0L to inform the operator at location A that the trafiic locking circuit is again closed. Also, the closing of front contact I29 of directional relay BWF at location B completes a circuit for illuminating lamp TL to inform the operator at location B that the traffic locking circuit is again closed. With directional relay BWF picked up closing front contact I30, a slow release repeater relay WFA is energized and picked up. The operator at location B next moves his signal control lever 2L to its left-hand position to complete a circuit for signal control relay L2AH, the circuit extending from terminal B2 over front contact I32 of repeater relay WFA, lever contact I3I, front contact I33 of track relay CITR, winding of relay LZAH and terminal C2. With relay LZAH picked up closing front contact I52 the signal L2A is operated to a proceed position to permit a westbound movement.

As the train advances west past signal L2A and enters track section CIT to shunt track relay CITR opening front contact I33, the signal control relay L2AH is deenergized closing back contact I53 with the result that the signal L2A is set at stop. The trafflc following relay BWFS is next picked up by current supplied over back contact 81 of track relay CITR and front contact I34 of repeater relay WFA, and relay BWFS is then retained energized over its stick circuit so that the signal control relay L2Al-I can be reenergized and signal L2A operated for a following westbound train because the circuit for relay LZAH is now completed at front contact I35 of the trafiic following relay BWFS. v

As long as the westbound train occupies the stretch between locations A and B, the trafiic locking circuit is held open the same as described hereinbefore but as soon as the westbound train reaches location A, the circuit is completed to reenergize the directional relay BWF and the directional repeater relay WFP.

Again it should be observed that an unauthorized movement of lever AB on the part of the operator at location A after the wayside signal LZA has been operated for a westbound tr-ain, does not cause signal LZA to be set at stop because repeater relay ASP at location A is retained energized over its stick circuit which includes back contact 35 of relay BEF, front contact I31 of relay WFP and its own front contact I38, and relay ABP on being retained energized holds the trafiic locking circuit completed at its front contacts Ill and H8.

Assuming the traffic locking circuit of Fig. 2 is conditioned for westbound trafi'ic in the manner explained above, the stretch of track is unoccupied and the operator at location A desires to send a train eastbound from location A, the operator at location A signals to the operator at location B by depressing his push button BPI to pole change the trafiic locking circuit by closing contacts I39 and I40 of push button BPI with the result that the directional relay SWF is reversed closing its reverse polar contact MI. Since front contact I42 of relay GWF is already closed the closing of reverse polar contact I4I of relay GWF completes the circuit for the signal bell TB and signals the operator at location A that the operator at location B desires a change in the direction of traffic. The operator at location B then moves his trafiic lever B6 to its normal position to close contact 93 to energize the repeater relay BGP, The movement of lever B6 to its normal position opens contacts I I9 and I20 to remove the directional relay BWF from connection with the trafiic locking circuit. With repeater relay BEP picked up closing front contacts I and IE the battery at location B is connected with th traffic locking circuit and opposes the battery at location A with the result that the repeater relay WFP is deenergized to open front contact I28 which in turn causes the lamp 0L at location A to be extinguished signaling the operator at location A that the operator at location B agrees to a change in the direction of traflic.

The operator at location A next moves his trafilc lever A8 to its normal position closing nor mal contacts I82 and IE3 to connect the directional relay GEF with the trafiic locking circuit, and to open contact I I6 which causes the repeater relay AtP to be deenergized and released to transfer the trafiic locking circuit from the battery at location A to direction relay GEF. The apparatus is now restored to its normal condition and the operator at location A can dispatch eastbound trains by operation of his signal lever 2B in the manner explained hereinbefore.

Although I have herein shown and described only two forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. Railway traffic controlling apparatus in combination with a'stretch of track extending between two spaced locations, a traflic governing signal at each end of the stretch for governing traffic through the stretch and a traffic locking circuit extendingbetween said locations responsive to traiiic occupying said stretch; two polarized directional relays one at each of said locations, said relays each characterized byretaining its front neutral contacts closed when the energizing current is reversed, a signal control relay at each location controlled by a front neutral contact of the directional relay to the same location and effective when picked up to cause the traffic governing signal of that location to be operated to a proceed position, manually controlled means partly at each location to connect either thedirectional relay atone location and the current source at the other location or vice versa with said trafiic locking circuit'to energize one or the other of said directional relays at normal polarity to control the respective signal control relay and cause operation of the corresponding traffic governing signal and establish the directicn of trafiic through said stretch, a signaling unit for each location, said signaling units each controlled over a reverse polar contact of the directional relay at the same location, and manually operable pole changing means at each location interposed in said traffic locking circuit to reverse the polarity 'of the current supplied by the source of the same location to said traffic locking circuit to cause at times a reversal of the directional relay at the opposite location to'operate the asso- V ciated signaling unit and at the same time retain the signal control relay energized.

2. Railway traiiic controlling apparatus in,

combination with a stretch of tracke'xtending between two interlockings each of which includes a wayside signal governing trafiic through the stretch, a signal control lever, a traiiic lever and a source of direct current; a traffic locking circuit including two line wires extending between said interlcckings, two retained neutral polarized relays one at each interlocking, circuit means partly at each interlocking including contacts of said traific levers to connect the polarized relay at one interlocking and the current source at the other interlocking or vice versa with said line wires to energize a selected one of said polarized relays at normal polarity to establish the direction of traffic between said interlockings, a signal control relay at each interlocking effective when energized to cause the wayside signal at the same interlocking to be operated to a proceed position, v

means at each interlocking including a front neutral contact of the polarized relay and a contact of the signal control lever of the same interlocking to control the associated signal control relay and cause operation of the corresponding wayside signal to its proceed position, a signaling unit at each interlocking located remote from the wayside signal at the same interlocking and con,-

trolled over a reverse polar contact of the polar such other interlocking has been operated to its proceed position.

3. Railway traflic controlling apparatus in combination with a stretch of track extending between two interlockings each of which includes a wayside signal governing traffic through the stretch, a signal control lever, a trafiic lever and a source of direct current; a trafiic locking circuit including two line wires extending between said interlockings, two retained neutral polarized relays one at each interlocking, circuit means partly at each interlocking including contacts of said trafllc levers to connect the polarized relay at one interlocking and the current source at the other interlocking or vice versa with said line wires to energize a selected one of said polarized relays at normal polarity to establish the direction of traffic between said interlockings, a signal control relay at each interlocking effective when energized to cause the wayside signal at the same interlocking to be operated to a proceed position, means at each interlocking including a front neutral contact of the polarized relay and a contact of the signal control lever of the same interlocking to control the associated signal control relay and cause operation of the corresponding wayside signal to its proceed position, a signal bell and a signal lamp at each interlocking, a pole changing push button at each interlocking interposed in said circuit means and each operative when depressed to reverse the connections of the current source of the same interlocking with said line wires to cause a reversal of the polarized relay at the other interlocking, circuit means at each interlocking including a front neutral contact of the associated polarized relay to operate the associated lamp to indicate the condition of the traffic locking circuit, and other circuit means including a reverse polar contact of the associated polarized relay to operate the associated bell.

- 4. Railway traffic controlling apparatus in combination with a stretch of track extending between a first and a second interlocking each of which includes a wayside signal governing traffic through the stretch and asource of direct current, said first interlocking having a wayside signal control relay and a trafi'ic control relay, said secondinterlocking having a wayside signal control lever interlocked with a traffic control lever provided with a lever lock and operable to a normal and a reverse and an indication position, a retained neutral polarized relay at each interlocking, a pair of line wires extending between said interlockings, a first circuit means including a front contact of said traffic control relay and a normal contact of said traffic control lever to connect the current source at said second interlocking and the polarized relay at said first interlocking with said line wires to energize that polarized relay at normal polarity, a second circuit means including a back contact of said traffic control relay and a reverse contact of said trafiic control lever to connect the current source at said first interlocking and the polarized relay at said second interlocking with said line wires to energize that polarized relay at normal polarity, means including an indication position contact of said traflic lever to connect its lever lock with said line wires, a signal bell at each interlocking each of which is controlled over a reverse polar contact of the associated polarized relay, a pole changing relay at said first interlocking having contacts interposed in said second circuit means for at times causing a reversal of the polarized relay at said second interlocking for operating the associated signal bell, a pole changing push button at said second interlocking interposed in said first circuit means for at times causing a reversal of the polarized relay at said first interlocking for operating the associated signal bell, means including a front neutral contact of the polarized relay and a front contact of the wayside signal control relay of the first interlocking for controllng the associated wayside signal, and means including a contact of said signal control lever for controlling the wayside signal at said second interlocking.

5. Railway traffic controlling apparatus in combination with a stretch of track extending between a first and a second interlocking each of which includes a wayside signal governing trafiic through the stretch and a source of direct current, a traffic control device at each interlocking operable to a first and a second position, a pair of line wires extending between said interlockings, a directional relay at each interlocking, a directional repeater relay at said second interlocking, said repeater relay having a pick-up voltage substantially equal to the combined voltages of said two sources of current, a first circuit means including a first position contact of each of said traffic devices to connect said repeater relay and the current source of said second interlocking and the directional relay of said first interlocking with said line wires to effectively energize that directional relay to establish traffic from the first to the second interlocking, a second circuit means including a second position contact of each of said traffic devices to connect the current source of said first interlocking and the directional relay of said second interlocking with said line wires to effectively energize that directional relay to establish traffic from the second to the first interlocking, and a signal bell at said second interlocking controlled over a front contact of said repeater relay to sound the bell when the traific device of the first interlocking is operated to its second position and the traffic device of the second interlocking is operated to its first position so that both sources and said repeater relay are connected in series over said line wires.

6. Railway traflic controlling apparatus comprising in combination with a stretch of railway track having a wayside signal at each of two spaced locations for governing traffic in opposite directions through the stretch and a two-wire traffic locking circuit extending between such locations for controlling the wayside signals in accordance with the positions of two manually controlled devices one at each location, a signal control relay at each location effective when energized to cause operation of the wayside signal at the, same location to a proceed position, an electromagnet at each location effective when energized to permit energization of the associated signal control relay, said electromagnet at a selected one of said locations characterized as a retained neutral polarized relay having a front neutral contact which permits the energization of the associated signal control relay, a current source at each location, a first circuit means including a contact of each of said devices closed at a first position thereof to connect the current source at said selected one location and the electromagnet at said other location to said traffic locking circuit to energize that electromagnet for permitting energization of the respective signal control relay and operation of the respective wayside signal to its proceed position, a second circuit means including a contact of each of said devices closed at a second position thereof to c0nnect the current source at said other location and said polarized relay at said one location to said traffic locking circuit to energize that relay for permitting the energization of the respective signal control relay and operation of the respective wayside signal to its proceed position, a signaling unit at said one location controlled over a polar contact of said polarized relay, and a manually operable pole changer at said other location interposed in said second circuit means to reverse at times the connection of the associated current source to the trafiic locking circuit to reverse the energization of said polarized relay and cause operation of said signaling unit while the wayside signal at said one location is retained at its proceed position.

7. Railway traflic controlling apparatus comprising in combination with a stretch of railway track having a Wayside signal at each of two spaced locations for governing traflic in opposite directions through the stretch and a two-wire trafiic locking circuit extending between such cations for controlling the wayside signals in accordance with which one of two directional relays one at each location is energized, a current source at each location, a trafiic lever at each location operable to a normal or a reverse position, a repeater relay for each of said trafiic levers, said repeater relay at one location controlled over a pick-up circuit including a reverse position contact of its trafiic lever and over a stick circuit including a back contact of the directional relay at said one location, said repeater relay at the other location controlled over a pick-up circuit including a normal position contact of its trafiic lever and over a stick circuit including a back contact of the directional relay at said. other location, a first circuit means including a front contact of the repeater relay at said one location and a reverse position contact of the trafiic lever at said other location to connect the current source'at said one location and the directional relay at said other location to said traflic locking circuit to energize that directional relay to control the associated wayside signal whereby a subsequent unauthorized movement of'the traflic lever at said one location is inefiective to disturb the control of the wayside signal, and a second circuit means including a front contact of the repeater relay at said other location and a normal position contact of the trafiic lever at said one location to connect the current source at said other location and the directional relay at said one location to said traffic locking circuit to energize that directional relay to control the associated wayside signal whereby a subsequent unauthorized movement of the trafiic lever at said other location is ineffective to disturb the control of the associated wayside signal.

JAMES J. VANI-IORN. 

